Abstract: This invention relates to provisioning wavelength-selective switches and reconfigurable optical add-drop multiplexers to minimize the bandwidth narrowing effect from the optical filters. Novel architectures and methods are disclosed that can significantly reduce bandwidth-narrowing on channels in a reconfigurable WDM network where a large number of optical filter elements are cascaded. Instead of blocking unused channels as in the prior art, unused channels are selectively provisioned depending on the state of their adjacent channels. Unused adjacent channels of an active channel are provisioned to follow the same path as the active channels. As each channels is deployed, the channel frequency is selected so as to minimize bandwidth narrowing.

Abstract: An optical transceiver has a communications mode and an optical time domain reflectometer (OTDR) mode. The transceiver comprises a transmitter channel and a receiver channel operable, in the communications mode, to respectively transmit and receive communications signals through respective external optical fibers. The transceiver also comprises a guide arrangement for guiding, in the OTDR mode, a reflected OTDR signal along a path from the transmitter channel into the receiver channel. A method of obtaining test data for an optical fiber in an optical data communications subsystem is also disclosed.

Abstract: A headend communications device communicates via a network to downstream network elements, such as cable modems coupled behind optical network units, and allocates and grants timeslots for upstream transmissions from the network elements. The headend communications device has a scheduler for managing and controlling timeslot allocations in a manner avoiding interference such as optical beat interference or FM carrier collisions. The scheduler identifies two or more cable modems or like customer network elements served by the headend communications device that will cause at least a pre-determined intolerable level of interference when allocated overlapping timeslots for upstream transmissions and prevents these two or more cable modems or network elements from being allocated and granted overlapping timeslots.

Abstract: An optical signal transmitter of the present invention includes: two phase modulating portions; a phase shifter which displaces carrier phases of two output lights from the phase modulating portions by ?/2; a multiplexing portion which multiplexes two signal lights, carrier phases of the two signal lights being made orthogonal to each other by the phase shifter; a drive signal electrode portion which supplies a differential data signal to each of four paths of interference optical waveguides, each of the two phase modulating portions having the interference optical waveguides, the differential data signal having an amplitude which is equal to a half-wave voltage V? of the two phase modulating portions; a drive amplifier which amplifies the differential data signal to be supplied to each of the four paths of the interference optical waveguides; a data bias electrode portion which supplies a total of four data bias voltages to two arms, each of the two phase modulating portions having the two arms; an orthogona

Abstract: Various embodiments of the present invention relate to pre-jam waveforms for enhanced optical break lock jamming effects. In various examples, pre-jam waveforms for enhanced optical break lock jamming effects may be implemented in the context of systems, methods, computer program products and/or algorithms.

Abstract: An apparatus includes an array of lasers, an array of electrical drivers, and optical filter. Each laser is configured to produce light in a corresponding wavelength-channel, wherein the wavelength-channels of different ones of the lasers are different. The electrical drivers are connected to directly modulate the lasers. Each driver produces a first driving current or voltage to cause a corresponding one of the lasers to be in a first lasing state and produces a different second driving current or voltage to cause the corresponding one of the lasers to be in a different second lasing state. The optical filter is connected to receive light output by the lasers. The optical filter selectively attenuates light from each of the lasers in the first lasing states thereof and to selectively pass light from each of the lasers in second lasing states thereof.

Abstract: A WDM signal light monitoring device includes a first monitor for monitoring input-side WDM main signal light and output-side WDM main signal light for each wavelength; and a second monitor for monitoring the first monitor by comparing a monitoring result received from an upstream WDM transmission device with a monitoring result of the first monitor, wherein the monitoring result of the first monitor is transmitted to a downstream WDM transmission device in the system.

Abstract: Since it is difficult to fast, simply monitor impairments of received signals with higher receiver sensitivity, a monitoring method for an optical communication system according to an exemplary aspect of the invention includes the steps of emitting lightwave signals to be modulated according to a data, forming dips at transitions between temporally consecutive groups of n symbols of the lightwave signals, wherein the dips are formed at each of (n?1) first transitions of the group, no dip is formed at the n-th transition on the lightwave signals, receiving the lightwave signals, extracting frequency components characterized by the numerical value n from received lightwave signals, and monitoring the received lightwave signals by using the frequency components.

Abstract: An apparatus including a polarization controller is described. The polarizer controller is communicatively coupled via a feedback loop to an evaluation module located near an optical receiver. The evaluation module is configured to measure polarization dependent loss (PDL) of an optical signal received at the optical receiver. The polarization controller is configured to receive feedback control data regarding the PDL from the evaluation module. Additionally, the polarization controller is configured to modify a state of polarization of the optical signal at an optical transmitter, which is communicatively coupled to the optical receiver, based on the feedback control data.

Abstract: An optical apparatus receives an upward signal light from a plurality of subscriber units, where the upward signal light is composed of a plurality of time slots corresponding to the plurality of optical subscriber units. The optical apparatus includes a driving unit configured to determine a respective required gain for light from each of the plurality of optical subscriber units, an amplifying section configured to amplify the upward signal light with the required gain corresponding to the time slots of the upward signal light, and a receiver configured to receive the amplified upward signal light.

Abstract: A system comprising a first optical line terminal (OLT) comprising a first integrated optical network unit (ONU), and a first OLT transceiver, and a second OLT coupled to the first OLT, wherein the second OLT comprises a second integrated ONU, and a second OLT transceiver. Included is a first OLT comprising an optical transceiver, at least one processor coupled to the optical transceiver, wherein the processor working in conjunction with the optical transceiver is configured to determine an upstream wavelength corresponding to a second OLT, join, via a first ONU in the first OLT, the second OLT using the upstream wavelength corresponding to the second OLT, and transmit data to the second OLT by the first OLT via the first ONU, wherein the second OLT comprises a second ONU.

Abstract: An optical transceiver apparatus includes a gain medium, a photoelectric converter, at least one AWG, and a partial reflection mirror. The at least one AWG includes two common ports and multiple branch ports. One of the two common ports functions as a signal sending port, and the other functions as a signal receiving port, where bandwidth of the signal sending port is less than that of the signal receiving port. The gain medium and the photoelectric converter are connected to one of the branch ports of the AWG. The AWG and the partial reflection mirror are configured to cooperatively perform wavelength self-injection locking on an optical signal provided by the gain medium, and output the optical signal through the signal sending port. The AWG is further configured to demultiplex an optical signal received by the signal receiving port to a branch port. A WDM-PON system is also provided.

Abstract: In an Optical Add-Drop Multiplexer, a drop section comprises a Wavelength Selective Switch (WSS) having at least one drop-port, the WSS being operative to couple a respective set of w (where w>1) wavelength channels from a received Wavelength Division Multiplexed (WDM) signal to each drop port. A respective 1:s power splitter is associated with each drop port. Each power splitter supplies the respective set of channels received from its drop port to each one of a corresponding set of coherent receivers. Each coherent receiver operates to receive a selected one of the respective set of channels.

Abstract: A technique for providing time division multiplexing (“TDM”) and wavelength division multiplexing (“WDM”) communication services to customer premises (“CP”) over a passive optical network (“PON”) includes multiplexing a downstream TDM signal with downstream WDM signals onto a fiber trunk line coupled between a central office and a remote node (“RN”), separating the downstream WDM signals from the downstream TDM signal at the RN with a wavelength selective filter, power splitting the downstream TDM signal at the RN onto a plurality of fiber access lines as split TDM signals; and recombining each of the WDM signals with a corresponding one of the split TDM signals onto a corresponding one of the fiber access lines.

Abstract: There are disclosed systems and methods for detecting whether an Optical Network Unit (ONU) in a network may be causing a communications interference due to laser overlap. In one embodiment, an Optical Line Terminal (OLT) selects a pair of ONUs suspected of possibly causing laser overlap. The OLT then grants a first window to a first ONU for transmitting a first message, and grants to another ONU different from the pair of ONUs a second window for transmitting a second message. If the first message is not received by the OLT, then the OLT indicates that the first ONU may be causing laser overlap. In another embodiment, the OLT grants to an ONU a window for transmitting a message to the OLT. If the message is not received by the OLT when expected, then the OLT indicates that the ONU may be causing laser overlap. Other embodiments are disclosed.

Abstract: An optical apparatus for use in an optical communications network, and a method of operating a network are described. The apparatus includes an input suitable for receiving a first continuous wave optical signal from a remote location on a network, and a modifying unit arranged to modify the first continuous wave optical signal to produce a second continuous wave optical signal having a wavelength which is different from the wavelength of the first continuous wave optical signal. A modulating unit is arranged to modulate the second continuous wave optical signal with data to produce a modulated second continuous wave optical signal.

Abstract: To enable signal position detection, frequency offset compensation, clock offset compensation, and chromatic dispersion amount estimation in a communication system based on coherent detection using an optical signal, even on a signal having a great offset in an arrival time depending on a frequency due to chromatic dispersion. An optical signal transmitting apparatus generates specific frequency band signals having power concentrated on two or more specific frequencies and transmits a signal including the specific frequency band signals. An optical signal receiving apparatus converts a received signal into a digital signal, detects positions of the specific frequency band signals from the converted digital signal, estimates frequency positions of the detected specific frequency band signals, and detects a frequency offset between an optical signal receiving apparatus and an optical signal transmitting apparatus.

Abstract: A remote control apparatus for controlling a plurality of remote controllable appliances includes a housing, an infrared signal receiving window and an infrared signal transmitting window defined in the housing. The remote apparatus determines the selected appliance and the selected function based upon a wireless signal carrying an identification transmitted by the mobile terminal, determines an infrared remote control code, and emits an infrared signal carrying the infrared remote control code. A light directing element received in the housing directs the infrared signal emitting by the infrared transmitting unit and the infrared remote control signal from the attached remote control to exit the housing through the infrared signal transmitting window, thereby controlling the selected appliance to execute the selected function.

Abstract: An optical-power-distribution (OPD) subsystem that provides means for supplying optical local-oscillator signals and optical-carrier signals to various optical line cards, without the need for each optical line card to have a corresponding individual laser source. In one embodiment, a single laser coupled to the OPD subsystem provides optical local-oscillator signals and optical-carrier signals to multiple optical line cards. In another embodiment, multiple lasers coupled to the OPD subsystem provide multiple optical local-oscillator signals and optical-carrier signals to a single line card. An OPD subsystem may provide significant power savings in the operation of the corresponding optical transport system, a reduction in the required equipment-cooling capacity, and an increase in the device-packing density within optical line cards and inside equipment cabinets that house optical line cards.

Abstract: A method of generating an optical radiation signal is to be implemented by an optical radiation signal generating device including a dual beam generating unit for receiving an original optical input signal, and a second-order fiber Bragg grating (FBG). The dual-beam generating unit is configured to generate, from the original optical input signal, first and second optical input signals having a phase difference therebetween. The second-order FBG is configured to receive the first and second optical input signals, and to radiate an optical radiation signal by interference between the first and second optical input signals.